Babbitt metal is a material used for manufacturing components such as bearing bushes and sleeves, which are friction pairs that directly engage with shafts or journals. Sliding bearing materials must possess excellent anti-friction properties, wear resistance, embeddability, conformability, corrosion resistance, and sufficient load-bearing capacity to reduce friction and wear, thereby extending the service life of the bearings. Bearing bushes are made from sliding bearing materials with good anti-friction properties, including metallic materials (such as copper alloys, aluminum alloys, and Babbitt metal) and non-metallic materials (such as plastics, graphite, rubber, and wood). Some metallic materials with good anti-friction properties have low strength (e.g., Babbitt metal) and are only cast as a layer on the surface of bearing bushes made from higher-strength materials, known as bearing liners. The part supporting the bearing liner is called the liner backing, commonly made from mild steel, cast iron, or bronze. To further improve the surface properties of the bearing liner, a thin layer of metal with even better anti-friction properties (such as indium) can be plated onto its surface. Bearing bushes manufactured from multiple layers of different metallic materials are called multilayer metal bearing bushes. Bearing bushes whose inner bore shape is largely unaffected by the shape of the bearing housing bore are called thick-walled bearing bushes; those whose inner bore shape primarily depends on the shape of the bearing housing bore are called thin-walled bearing bushes. Thin-walled bearing bushes are widely used in mass-produced machinery such as internal combustion engines and air compressors.

Compressive strength and fatigue strength, wear resistance, run-in capability, friction compatibility to prevent adhesion to journals, conformability to compensate for initial poor fit of sliding surfaces, embeddability to allow hard particles to embed and reduce journal scoring, thermal conductivity, corrosion resistance, manufacturability, cost, etc.